Missing toolbar and cannot resize areas?
To split or join areas, you can either drag on the shaded corner with  LMB, or you can  RMB on the edge between areas and select Split or Join.

Once you have done that, move the mouse over the area you want to replace and you will see an arrow appear which indicates which area will replace which.

To confirm, either release  LMB (if you were dragging from the corner widget), or click with  LMB if you use the  RMB method.



To resize areas, drag the edge of the area with  LMB:



To change an area's type, click the drop down on the far left of the header and select an editor type:



So, to fix your layout:


Change the top 3D view to an info area and resize it so that only the header is visible.
Change the timeline to a 3D view




For more information, see the wiki.